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  <title>Submits a request to create a prepared statement with the 
  given parameters, and waits for completion</title>
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  <div id="layout-content"><div id="function.pg-prepare" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">pg_prepare</h1>
  <p class="verinfo">(PHP 5 &gt;= 5.1.0, PHP 7)</p><p class="refpurpose"><span class="refname">pg_prepare</span> &mdash; <span class="dc-title"> Submits a request to create a prepared statement with the 
  given parameters, and waits for completion</span></p>

 </div>

 <div class="refsect1 description" id="refsect1-function.pg-prepare-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="methodname"><strong>pg_prepare</strong></span>
    ([ <span class="methodparam"><span class="type">resource</span> <code class="parameter">$connection</code></span>
   ], <span class="methodparam"><span class="type">string</span> <code class="parameter">$stmtname</code></span>
   , <span class="methodparam"><span class="type">string</span> <code class="parameter">$query</code></span>
   ) : <span class="type">resource</span></div>

  <p class="para rdfs-comment">
    <span class="function"><strong>pg_prepare()</strong></span> creates a prepared statement for later execution with 
    <span class="function"><a href="pg_execute.html" class="function">pg_execute()</a></span> or <span class="function"><a href="pg_send_execute.html" class="function">pg_send_execute()</a></span>. 
    This feature allows commands that will be used repeatedly to 
    be parsed and planned just once, rather than each time they are executed. 
    <span class="function"><strong>pg_prepare()</strong></span> is supported only against PostgreSQL 7.4 or
    higher connections; it will fail when using earlier versions.
  </p>
  <p class="para">
    The function creates a prepared statement named <code class="parameter">stmtname</code> from the <code class="parameter">query</code> 
    string, which must contain a single SQL command. <code class="parameter">stmtname</code> may be &quot;&quot; to 
    create an unnamed statement, in which case any pre-existing unnamed 
    statement is automatically replaced; otherwise it is an error if the 
    statement name is already defined in the current session. If any parameters 
    are used, they are referred to in the <code class="parameter">query</code> as $1, $2, etc.
  </p>
  <p class="para">
    Prepared statements for use with <span class="function"><strong>pg_prepare()</strong></span> can also be created by 
    executing SQL <em>PREPARE</em> statements. (But <span class="function"><strong>pg_prepare()</strong></span> is more flexible since it 
    does not require parameter types to be pre-specified.) Also, although there 
    is no PHP function for deleting a prepared statement, the SQL <em>DEALLOCATE</em>
    statement can be used for that purpose.
  </p>
 </div>


 <div class="refsect1 parameters" id="refsect1-function.pg-prepare-parameters">
  <h3 class="title">参数</h3>
  <p class="para">
   <dl>

    
     <dt>
<code class="parameter">connection</code></dt>

     <dd>

      <p class="para">
       PostgreSQL database connection resource.  When 
       <code class="parameter">connection</code> is not present, the default connection 
       is used. The default connection is the last connection made by 
       <span class="function"><a href="pg_connect.html" class="function">pg_connect()</a></span> or <span class="function"><a href="pg_pconnect.html" class="function">pg_pconnect()</a></span>.
      </p>
     </dd>

    
    
     <dt>
<code class="parameter">stmtname</code></dt>

     <dd>

      <p class="para">
       The name to give the prepared statement.  Must be unique per-connection.  If
       &quot;&quot; is specified, then an unnamed statement is created, overwriting any
       previously defined unnamed statement.
      </p>
     </dd>

    
    
     <dt>
<code class="parameter">query</code></dt>

     <dd>

      <p class="para">
       The parameterized SQL statement.  Must contain only a single statement.
       (multiple statements separated by semi-colons are not allowed.)  If any parameters 
       are used, they are referred to as $1, $2, etc.
      </p>
     </dd>

    
   </dl>

  </p>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-function.pg-prepare-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   A query result resource on success 或者在失败时返回 <strong><code>FALSE</code></strong>.
  </p>
 </div>

 
 <div class="refsect1 examples" id="refsect1-function.pg-prepare-examples">
  <h3 class="title">范例</h3>
  <p class="para">
   <div class="example" id="example-2510">
    <p><strong>Example #1 Using <span class="function"><strong>pg_prepare()</strong></span></strong></p>
    <div class="example-contents">
<div class="phpcode"><pre><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #FF8000">//&nbsp;Connect&nbsp;to&nbsp;a&nbsp;database&nbsp;named&nbsp;"mary"<br /></span><span style="color: #0000BB">$dbconn&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">pg_connect</span><span style="color: #007700">(</span><span style="color: #DD0000">"dbname=mary"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">//&nbsp;Prepare&nbsp;a&nbsp;query&nbsp;for&nbsp;execution<br /></span><span style="color: #0000BB">$result&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">pg_prepare</span><span style="color: #007700">(</span><span style="color: #0000BB">$dbconn</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"my_query"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">'SELECT&nbsp;*&nbsp;FROM&nbsp;shops&nbsp;WHERE&nbsp;name&nbsp;=&nbsp;$1'</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">//&nbsp;Execute&nbsp;the&nbsp;prepared&nbsp;query.&nbsp;&nbsp;Note&nbsp;that&nbsp;it&nbsp;is&nbsp;not&nbsp;necessary&nbsp;to&nbsp;escape<br />//&nbsp;the&nbsp;string&nbsp;"Joe's&nbsp;Widgets"&nbsp;in&nbsp;any&nbsp;way<br /></span><span style="color: #0000BB">$result&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">pg_execute</span><span style="color: #007700">(</span><span style="color: #0000BB">$dbconn</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"my_query"</span><span style="color: #007700">,&nbsp;array(</span><span style="color: #DD0000">"Joe's&nbsp;Widgets"</span><span style="color: #007700">));<br /><br /></span><span style="color: #FF8000">//&nbsp;Execute&nbsp;the&nbsp;same&nbsp;prepared&nbsp;query,&nbsp;this&nbsp;time&nbsp;with&nbsp;a&nbsp;different&nbsp;parameter<br /></span><span style="color: #0000BB">$result&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">pg_execute</span><span style="color: #007700">(</span><span style="color: #0000BB">$dbconn</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"my_query"</span><span style="color: #007700">,&nbsp;array(</span><span style="color: #DD0000">"Clothes&nbsp;Clothes&nbsp;Clothes"</span><span style="color: #007700">));<br /><br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</pre></div>
    </div>

   </div>
  </p>
 </div>

 
 <div class="refsect1 seealso" id="refsect1-function.pg-prepare-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li class="member"><span class="function"><a href="pg_execute.html" class="function" rel="rdfs-seeAlso">pg_execute()</a> - Sends a request to execute a prepared statement with given parameters, and waits for the result</span></li>
    <li class="member"><span class="function"><a href="pg_send_execute.html" class="function" rel="rdfs-seeAlso">pg_send_execute()</a> - Sends a request to execute a prepared statement with given parameters, without waiting for the result(s)</span></li>
   </ul>
  </p>
 </div>

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